RU2802921C1 - Three-product hydrocyclone - Google Patents

Abstract

FIELD: treatment of sludge mine wastewater.

SUBSTANCE: invention can be used to purify water from sludge sedimentation tanks of processing plants. The additional cleaning chamber is made in the form of a truncated cone with a large base in the upper part, and the height difference between the upper pipe 7 (H₃), drain pipe 6 (H₂) and supply pipe 2, pipe diameter 4 (d_p), discharge pipe 3 (H₁) and branch pipe 6, feed capacity (Q₀), area of the supply pipe (S₀), maximum particle diameter of the sludge (d₂) removed through the drain pipe, density of solid particles (ρ_s) and water (ρ_w), streamline coefficient (с) and cyclone diameter (D) is related by dependencies: Н₃+ Н₂ = 0,5(Q₀ /S₀)²/g, Н₃ = (2d₂*с * ρ_s) (3ρ_w)^-1, Н₁ = 5*D, 2Кd₂ ρ_т g(3ρ_w)^-1 = [4Q₀(π d_п ²)^-2]² where g is the free fall acceleration, K is a safety factor equal to 1.21.

EFFECT: improved efficiency of polluted water treatment, saving water by increasing the return of treated water to the sump, i.e. recycling water supply and reducing wear of the transfer pump rotor blades.

1 cl, 1 dwg

Description

The invention relates to devices for purifying sludge mine wastewater and can be used to purify water from sludge settling tanks of processing plants.

A three-product hydrocyclone is known (A.S. 476033, published 07/05/1975, Bulletin 25), consisting of a cylindrical body, an inlet pipe for supplying the initial mixture, and a drain pipe for releasing the clarified product. A cylindrical chamber for additional cleaning with an outlet pipe is adjacent to the upper part of the housing.

The disadvantage of a hydrocyclone is the impossibility of releasing a mixture of water and small particles (0.5 mm) of rock through the outlet pipe, since their mixture has a density greater than the density of water, and this hydrocyclone is designed to separate the lighter fraction (oil) from water.

The closest in technical essence is a three-product hydrocyclone (Pat. 1773495, A1. Publ. 1992.11.07), including a cylindrical-conical body, a tangential inlet pipe for supplying the initial mixture, a diaphragm with a vertical mixture outlet pipe fixed in it. Adjacent to the upper part of the housing is a cylindrical chamber for additional purification with two outlet pipes for releasing, respectively, the intermediate product and the upper product.

The disadvantage of a hydrocyclone is the possibility of particles passing through the vertical outlet pipe getting into the intermediate and upper product pipes. In this case, the entry of particles with a particle size of 0.1-0.5 mm into the upper product nozzle will lead to increased wear of the blades of the feed slurry pump. To prevent this, it is necessary to supply 30 m ³ /day of clean water to the underground sludge storage facility (for the conditions of the Gaisky GOK), which is a significant negative factor for the environment and additional energy costs.

The purpose of the proposed technical solution is to increase the efficiency of mine water treatment and save water by increasing the return of purified water to the sump, i.e. circulating water supply and reducing wear on the rotor blades of the transfer pump.

This goal is achieved by the fact that in the known three-product hydrocyclone, including a cylindrical-conical body 1 with a tangential supply pipe 2, a lower discharge pipe 3, a vertical drain pipe 4, an additional cleaning chamber 5 with a drain pipe 6 placed in it for draining the intermediate product and an upper pipe 7 to drain clarified water, the additional purification chamber is made in the form of a truncated cone with a large base in the upper part, and the height difference between the upper pipe 7 (H ₃ ), drain pipe 6 (H ₂ ) and supply pipe 2, the diameter of pipe 4 (d _p ), discharge pipe 3 (H ₁ ) and pipe 6, feed capacity (Q ₀ ), area of the supply pipe (S ₀ ), maximum diameter of sludge particles (d ₂ ), removed through the drain pipe, density of solid particles (ρ _t ) and water (ρ _in ), streamlining coefficient (c) and cyclone diameter (D) are related by the following dependencies:

H ₃ + H ₂ + H ₁ = 0.5(Q ₀ /S ₀ ) ² /g (1)

where H ₃ is the difference in height between the upper and drain pipes, m;

H ₂ - height difference between the drain and supply pipes, m;

H ₁ - height difference between the supply and sand pipes, m;

Q ₀ - feeding capacity, m ³ /s;

S ₀ - area of the supply pipe, m ² ;

g - free fall acceleration, m/s ² .

H ₃ = (2d ₂ *c * ρ _t ) (3ρ _in ) ^-1 (2)

where d ₂ is the maximum diameter of sludge particles, m;

c - streamlining coefficient;

ρ _t - particle density, kg/ ^m3 ;

ρ _in - density of water, kg/m ³ .

H ₁ = 5D (3)

where D is the diameter of the cyclone, m.

2 K d ₂ ρ _t g(3ρ _in ) ^-1 = [4Q ₀ (π d _p ² ) ^-1 ] ² (4)

where K is the safety factor equal to 1.21;

d ₂ - maximum diameter of sludge particles removed through the drain pipe, m;

d _p - diameter of the vertical drain pipe, m.

In fig. 1 shows a general view of the device.

A three-product hydrocyclone consists of a cylindrical-conical body 1, a tangential supply pipe 2 for supplying the initial mixture, fixed in the cylindrical part of the cylindrical-conical body 1. In the upper end part of the cylindrical-conical body 1 there is a vertical drain pipe 4, an additional cleaning chamber 5 with a drain pipe 6 placed in it for draining intermediate product and upper pipe 7 for draining clarified water. The lower discharge pipe 3 is fixed in the lower part of the cylindrical-conical body 1. The additional cleaning chamber 5 is made in the form of a cone, rigidly fixed in the drain pipe 4 and expanding from pipe 4 to pipe 7.

The device works as follows.

Initial supply - sludge-contaminated water is supplied through the tangential supply pipe 2 into the cylindrical-conical housing 1. Large particles (0.5 - 5 mm) are pressed against the walls of the cylindrical-conical housing 1 due to centrifugal force and, due to the friction force, lose speed, fall down and through the lower discharge pipe 3 enters the lower collection (not shown in the drawing). As practice shows, to ensure the capture of large particles, the height of the cylindrical-conical body 1 should be equal to H ₁ = 5D. Smaller particles (0.1 mm) do not reach the wall of the cylindrical-conical body 1 and, with an ascending flow of water, enter the vertical drain pipe 4, and then into the additional cleaning chamber 5 and are removed through the drain pipe 6 and enter the lower collection. In this case, the pressure on the drain pipe is determined by formula (2), which will ensure that particles of size (d ₂ ) stop rising and are removed through the drain pipe 6. Particles with a diameter of less than 0.2 mm rise higher and fall together with water into the upper pipe 7 and then return to their original diet. Sludge particles larger than 0.2 mm cannot enter the upper pipe 7, since the speed of their fall in the water is greater than the vertical speed of water at the level of the upper pipe (the additional cleaning chamber 5 is made in the form of a cone and the water flow speed decreases with increasing height). It has been established that particles with a particle size of 0.2 mm do not have a significant effect on the wear of slurry pump blades. To ensure the required flow through the upper pipe 7, the dynamic pressure at the outlet of the tangential supply pipe is determined by formula (1). To ensure the speed of soaring in the liquid of particles with a size d ₂ = 0.2 mm at the level of the drain pipe 6, condition (4) must be met.

An example of calculating a three product hydrocyclone Fig. 1

Horizontally, the maximum size of solid particles going into the upper drain is their speed of falling in the water:

where: ρ _m and ρ _in - the corresponding planes of the material and water, KG/m ³ ;

g - free fall acceleration, m/s ² ;

d - max diameter of particles in purified water, m.

Therefore, at the upper level of the middle drain pipe, the vertical component of the pulp velocity should not be greater than ( - zanaf coefficient equal to 1.1):

Pulp consumption through sand nozzle:

where: S1 is the cross-sectional area of the sand packing ( ).

Pulp flow through the middle nozzle (pipe):

where S2 is the area of the middle pipe ( )

The vertical component of the velocity at the level of the upper part of the middle pipe is determined from the molasses continuity equation:

where: D ₂ is the diameter of the cyclone at the level of the upper part of the pipe, m.

From the equation D2 is found _:

We accept D ₂ = 1060 mm.

Actual pulp velocity in a given section:

Consequently, particles larger than 0.2 mm will not be able to rise above this level.

Relative water savings due to the use of a cyclone:

Thus, the use of the invention will make it possible to use a hydrocyclone for the purification of multiphase liquids containing coarsely dispersed impurities that differ in specific gravity, both higher and lower than the specific gravity of the liquid being treated. Compared to the prototype, the proposed hydrocyclone has the following advantages: the ability to obtain the required degree of purification by thickening the fraction without changing the open cross-section of the drain pipe, and does not affect the operating mode of the hydrocyclone. Removing sludge from liquids ensures their clarification and subsequently makes it possible to reduce abrasive wear of pumps when pumping liquids to the surface of mine workings, as well as to use clarified water for reuse for mining enterprise tasks.

Claims (19)

A three-product hydrocyclone, including a cylindrical-conical body 1 with a tangential supply pipe 2, a lower discharge pipe 3, a vertical drain pipe 4, an additional cleaning chamber 5 with a drain pipe 6 placed in it for draining the intermediate product and an upper pipe 7 for draining clarified water, characterized in that that the additional cleaning chamber is made in the form of a truncated cone with a large base in the upper part, and the height difference between the upper pipe 7 (H ₃ ), drain pipe 6 (H ₂ ) and supply pipe 2, the diameter of the pipe 4 (d _p ), the discharge pipe 3 (H ₁ ) and pipe 6, feed capacity (Q ₀ ), area of the supply pipe (S ₀ ), maximum diameter of sludge particles (d ₂ ) removed through the drain pipe, density of solid particles (ρ _t ) and water (ρ _c ), streamlining coefficient (c) and cyclone diameter (D) are related by the following dependencies: H ₃ + H ₂ + H ₁ = 0.5(Q ₀ /S ₀ ) ² /g (1) where H ₃ is the difference in height between the upper and drain pipes, m; H ₂ - height difference between the drain and supply pipes, m; H ₁ - height difference between the supply and sand pipes, m; Q ₀ - feeding capacity, m ³ /s; S ₀ - area of the supply pipe, m ² ; g - free fall acceleration, m/s ² ; H ₃ = (2d ₂ *c * ρ _t ) (3ρ _in ) ^-1 (2) where d ₂ is the maximum diameter of sludge particles, m; c - streamlining coefficient; ρ _t - particle density, kg/ ^m3 ; ρ _in - density of water, kg/ ^m3 ; H ₁ = 5D (3) where D is the diameter of the cyclone, m; 2 K d ₂ ρ _t g(3ρ _in ) ^-1 = [4Q ₀ (π d _p ² ) ^-1 ] ² (4) where K is the safety factor equal to 1.21; d ₂ - maximum diameter of sludge particles removed through the drain pipe, m; d _p - diameter of the vertical drain pipe, m.